Create Techno with a Laser Harp

Ever wanted to make your own techno music, but are tired of the standard midi controller? Well, you could build a harp (of all instruments) out of lasers and then play it by breaking the beams of light. See how it’s done.

The harp is connected to the software synthesizer, the TAOS sensor array sits on the floor in its own stand. The array above the harp is just made up of mirrors for added p’zazz.

How it works:

Basically an Arduino connects to a 12-bit DAC chip (TLV5618) using the SPI 3 wire interface. It sends numbers on a timer interrupt to the DAC to specify where the beams are, 0, 455, 900, etc… all the way up to 4095 for 10 beams. It holds each position for about 500uS (half a millisecond) and switches laser blanking on (or is that “off”) for this time. When it reaches the end it brings the mirror back to the start position. The output of the DAC chip is 0-5V – this is then converted to -5v / +5v using a TL082 Opamp chip from Radio shack. Finally it’s passed through a Balanced Line Driver chip to give the full (-/+) 10v ptp) differential signal required by the mirror (laser galvanometer) amplifier.